User Agent: Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.1; Trident/4.0; GTB7.5; CNS_UA; AD_LOGON=4C47452E4E4554; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; Media Center PC 6.0; .NET4.0C; Tablet PC 2.0; InfoPath.3; .NET4.0E; CNS_UA; AD_LOGON=4C47452E4E4554)
Steps to reproduce:
1. At first boot, noti bar's wifi quick setting menu select for context menu
2. Wifi activity is searching ap lists and then select some ap with password
3. On wifi auth dialog, press back button
Actual results:
In this case, back button is not working or if it is working, it is not working to do in second time
When back button is not working, ok button is also not working.
Expected results:
dialog should be closed

This issue occurs on earliest b2g-32 branch build ID 20140718120320, and also occurs on earliest 2.0 Aurora branch build ID 20140609144129 - meaning that the whole 2.0 branch is affected with this bug.
We attempted a reverse-regression window in Central to find out what fixed the issue, but the broken build's behavior is different than this original bug. Bug 1050402 describes the issue, where options in Settings cannot be accessed when Settings is invoked by another app (in other words can't execute Step 5 of Comment 5). Perhaps the fix for bug 1050402 could somehow also fix this bug but we're not sure.
We then went further back in Central (before central branched into 2.0 Aurora), attempting to find the actual window where there's a last working and first broken with behaviors matching this bug, with no avail. In between last working and first broken, there is a bug lasting several weeks that a user cannot turn on Wifi in Settings if Wifi is invoked via notification bar. (another way of can't execute Step 5 of Comment 5)
Therefore we decided a regression window is not possible in this situation.

(In reply to Tim Guan-tin Chien [:timdream] (MoCo-TPE) (please ni?) from comment #9)
> Triage: blocking, but Arthur said it should be already fixed in 2.0. Assign
> to him to find the dup/patch for uplift.
Assigning and NI Arthur chen for above, please re-assign if needed.

There are a lot of files on comments. I thinks the patches as page_transitions.js, settings_service.js.
I verified to do by this patch. But On Quick setting > Wi-Fi menu, Settings main screen display and then w-fi settings display. It takes long time. Could you improve the time issue?

By this patches, back button is alived. But I found the other.
When wi-fi window creats by Quick setting, if back button press,
setting window closed. and then as setting menu, Wi-Fi window is focused.(not setting main window).
In addition, through the window, if I tried to active tethering, tethering's dialog don't work ok button.
repo step
Quick setting -> wifi window -> back button
setting menu -> back button to setting's main screen -> Internet sharing -> Wi-Fi hotspot on
-> tethering dialog ok click

I have tested it and the back button works properly.
When i have selected a ap with password, then is open a wifi auth dialog and pressing back button i can close it and return to the apn list.
I have tested using flame 2.1 , Gecko f816f7e Gaia c7b55ed.